Nest survival of forest birds in the Mississippi Alluvial Valley

In the Mississippi Alluvial Valley flood control has led to a drastic reduc tion in the area of forest habitat and altered the patchwork of forest cove r types. Silvicultural management of the the remaining fragmented forests h as changed to reflect the altered hydrology of the forests, current economi c conditions of the area, and demand for forest products. Because forest ty pe and silvicultural management impact forest birds, differences in avian p roductivity within these forests directly impact bird conservation. To assi st in conservation planning, we evaluated daily nest survival, nest predati on rates, and brood parasitism rates of forest birds in relation to differe nt forest cover types and silvicultural management strategies within this f loodplain. Within bottomland hardwood forests,, nest success of blue-gray g natcatcher (Poliptila caerulea, 13%), eastern towhee (Pipilo erythrophthala mus, 28%), indigo bunting (Passerina cyanea, 18%), northern cardinal (Cardi nalis cardinalis, 22%), and yellow-billed cuckoo (Coccyzus americanus, 18%) did not differ from that within intensively managed cottonwood plantations . However, average daily survival of 542 open-cup nests of 19 bird species in bottomland hardwoods (0.9516 +/- 0.0028, similar to 27% nest success) wa s greater than that of 543 nests of 18 species in cottonwood plantations (0 .9298 +/- 0.0035, similar to 15% nest success). Differences in daily nest s urvival rates likely resulted from a combination of differences in the pred ator community - particularly fire ants (Solenopsis invicta) - and a marked difference in species composition of birds breeding within these 2 forest types. At least 39% of nests in bottomland hardwood forests and 65% of nest s in cottonwood plantations were depredated. Rates of parasitism by brown-h eaded cowbirds (Molothrus ater) were greater in managed cottonwoods (24%) t han in bottomland hardwoods (9%). Nest success in planted cottonwood planta tions for 18 species combined (similar to 14%). and for yellow-breasted cha t (Iteria virens, 7%), eastern towhee (14%), indigo bunting (14%), and nort hern cardinal (17%) did not differ from nest success in cottonwood plantati ons that were coppiced from root sprouts following pulpwood harvest. Within bottomland hardwood forests, uneven-aged group-selection timber harvest re duced the combined daily nest survival of all species from 0.958 to 0.938, which reduced nest success by about 14%. Specifically, timber harvest reduc ed nest success of species chat nest in the forest midstory and canopy such as Acadian flycatcher (Empidonax virescens) - from 32% before harvest to 1 4% after harvest. Conversely, those species that nest primarily in the shru bbery understory - such as northern cardinal - were not affected by timber harvest and maintained an overall nest succcess of about 33%. Thus, birds n esting in the understory of bottomland hardwood forests are not adversely i mparted by selective timber harvest, but there is a short-term reduction in nest success for birds that nest in the canopy and midstory.